Connections Frame-Rigid (esasd.02)

 

esasd.02

The esasd.02 module is a tool for designing rigid and semi-rigid connections in steel frames.

Highlights
Capacity and stiffness of each connection subcomponent are calculated according to EN 1993-1-8:2005; DIN 18800: 1990 Teil 1, and BS 5950-1:2000.
Various joint configurations can be analysed -- girder-to-column knee-, cross-, single and double T-joints, splices (bolted and welded) and base-plate connections.
Connections between hot-rolled I-sections are covered, as well as between beams with hollow sections and I-section columns.
Beams can be connected along the weak or strong axis of a column.
Modelling tools allow for rectangular or triangular ribs, diagonal or perpendicular stiffeners, etc..
Both standard or pre-stressed bolts can be designed.
Clear contextual dialogues are provided separately for end-plates, bolts, ribs, stiffeners, backing plates.
The normative prescriptions are followed for each joint component, including checks for plate dimensions (pitch, gage, edge distance) vs. bolt size, minimal weld size.
Additional checks for the practical feasibility are also performed (gap sizes vs. wrench size).
Calculated and initially assumed joint stiffness are compared; the derived moment-rotation diagram of the joint is displayed; Calculated joint stiffness may be used to model the frame with flexible joints. (the esa.09 module is required).
If required, a joint can be further optimised in an interactive manner.

Modelling

  • Connections may be defined between symmetric or asymmetric I-sections, between I-section columns and RHS beams. Beams can be connected to both the web or flange of a column;
  • Haunches, or variable height of the connected members is also taken into account in the analysis;
  • Connections with either two or four bolts per row are supported;
  • Bolt libraries are provided for fast and input definition of the connection. Concrete and anchor data is also available for the design of column bases.

The following types of additional strengthening are available:

  • Haunches -- mode from T-profiles, cut from I-profiles, welded plates;
  • Backing plates on webs of beams and columns;
  • Triangular and rectangular stiffeners.

For column base-plate connections specifically, the following types of additional strengthening are allowed:

  • Haunches -- made from T-profiles, cut from I-profiles, welded plates;
  • Triangular and rectangular stiffeners;
  • Flange ribs (wideners);
  • Shear keys (shear irons);
  • For anchors - straight or curved anchors are supported, with or without circular plates at their ends, as well as anchors from plain or high-bond (ribbed/deformed) bars.

Calculation

  • Rigid and semi-rigid connections are checked for the effect of bending moments (around major axis), shear forces and normal forces.
  • When the analysis is performed according to the EUROCODE, rules from the following standards are taken into account:
    • EN 1993-1-1:2005 - General rules and rules for buildings;
    • EN 1993-1-8:2005, Design of joints, chapters 1--6.
  • The following components are checked:
    • column web panel in shear;
    • column web in compression;
    • beam flange and web in compression;
    • haunch in compression;
    • column flange in bending;
    • column web in tension;
    • end-plate in bending;
    • beam web in tension;
    • bolts/anchors in tension;
    • bolts/anchors in shear;
    • bolts/anchors in bearing;
    • concrete in compression;
  • The following components are checked in the case of connection to the web of a column:
    • Column web in bending and punching;
    • Bolts in tension;
    • End plate in bending;
    • Beam web in tension;
    • Beam flange and web in compression.
  • CIDECT regulations are used for the design of column bases under RHS columns*, and plate-to-plate splices* of RHS elements. The methods described in the reference are used to calculate connection limit states. The formulae in the national codes (EN 1993-1-8:2005, DIN 18800:1990 Teil 1 or BS 5950-1:2000) calculate the capacities of the individual components; the EUROCODE 3 rules are used by default;
  • Classification is performed by stiffness and by strength. Ductility classes are determined for bolted and welded joints;
  • Interaction with normal forces in the connected members is taken into account as prescribed in the code;
  • Settings according to national annexes are also available. An important feature is the modification to the triangular limit rule, available in the French national annex;
  • EUROCODE recommendations are used when analysing any concrete parts in a connection;
  • Although national codes are followed in the connection analysis, many of the used parameters remain editable:
    • safety factors,
    • geometry defaults related to the positioning of bolts (limits for bolt spacing and edge distances);
    • slip and torque factors for pretensioned bolts, etc.

Rigid and semi-rigid joints

The program compares the calculated joint stiffness with the stiffness originally used in the calculation model:

  • A warning is sent to the user if the difference is outside allowable limits;
  • The calculated stiffness can then be automatically taken into account in the analysis model;
  • Linear or non-linear springs may be derived based on the component method and assigned to nodes in the structure;
  • This automated closed-loop process enables the engineer to use simpler and cheaper semi-rigid connections, reducing the price of the structure, both related to material and labour costs.

Result output

  • After calculation, the critical load combination or load case is shown to the user;
  • the limiting component in the designed connection is also indicated;
  • If required, the joint can be further optimised in an interactive manner.

Reporting

SCIA Engineer provides a detailed report of the performed connection analysis:

  • The connection design and monodrawings can be included in the Engineering Report or document;
  • Calculation reports are organised in table form to keep the report concise;
  • The “detailed connection drawing” (esadt.02) wizard module automatically generates detailed dimensioned drawings for all parts of the connection.

rotational stiffness is not calculated in the case of RHS column base connection and RHS plate-to-plate splices.

Examples

  • Beam-to-column connections: end-plate (bolted)or welded connection; knee-joints, single and double T-joints, cross-joints;

  • Beam-to-beam splice connections with end-plates;

  • Column base: bolted base-plate connection.

22/10/2013